Problems with quicktime

[Brand]

I think I'm having problems with quicktime. Today I updated to the newest version after that Itunes whould no longer work (it just would not open). So I went back to yesterdays restore point Itunes still doesn't work but now I get the windows "iTunes has encountered a problem and needs to close. We are sorry for the inconvenience." Also trillian won't work, which I didn't think about untill I thought I'd install it again to see if it would fix it but the install crashes when it gets to quicktime. I don't know what's up with it. Quicktime was fine untill today so wouldn't going back to restore point before I updated it fix it? I'm a bit confused.

Oh and I'm running
Windows XP SP2
I also have the CCCP installed but that's never given in problems with quicktime. Also of note I can still watch quicktime movies.

Any help would be highly appreciated. Thanks.

[Brand]

Ok now I know I am having some series problems with quicktime. I went back to a restore point last week way before I did anything and it was still no good. So I once again re-installed the itunes and quicktime pack and I got this when installing.
http://img503.imageshack.us/img503/6711/quicktimeerror3cn.gif

I've tried to install quicktime 7.0.3 for windows by it's self because I read somewhere else that would fix the problem but it tells me it can't install because a newer version of quicktime is already installed.

Any help would be really really really appreciated. This is starting to drive me nuts.

[Brand]

Ok I uninstalled them and re-installed them and quick time seems to be working fine but when I double click on itunes it looks like it is going to open but it just doesn't.

Any help would be highly, highly appreciated, pretty please.